1. Renewable Energy
Chapter 18

2. 18-1 Renewable Energy Today
Objectives 1. List six forms of renewable energy, and compare their advantages and disadvantages. 2. Describe the differences between passive solar heating, active solar heating, and photovoltaic energy. 3. Describe the current state of wind energy technology. 4. Explain the differences in biomass fuel use between developed and developing nations. 5. Describe how hydroelectric energy, geothermal energy, and geothermal heat pumps work.

3. Renewable Energy – energy from sources that are constantly being formed Solar, wind, hydro, and geothermal

4. Solar Energy
Most all renewable NRG comes directly or indirectly from the sun

5. Passive Solar Energy
Use the sun’s NRG to heat something directly

6. A passive solar home
Ceilings heavily insulated
Thick walls and floors
South-facing double paned windows
Shade trees for summer
Insulated windows

8. Active Solar Heating
Uses collectors to gather the sun’s energy
Collectors on roofs capture the sun’s NRG and heat a liquid which flows to a heat exchanger which heats water for the building

10. About 8% NRG used in US is used to heat water

11. Photovoltaic cells convert the sun’s energy into electricity
No moving parts
Produce a small electric current

12. Need extended periods of sunlight
Electricity stored in batteries
Provides about 1 million households with electricity

15. Wind Power
Converts the movement of wind into electrical energy
Faster growing NRG source

20. Biomass
When plant material, manure, or any other organic matter is used an NRG source
Include wood and dung (can cause air pollution and habitat destruction)

22. Other source include methane (gas given off by decomposition) and alcohol (ethanol- fermentation of agriculture wastes)
Gasohol – blend of gasoline and ethanol; less air pollution then gas

23. Hydroelectricity
NRG produced by moving water
20% of the world’s electricity
Dams are expensive to build but inexpensive to operate

24. Advantages: No air pollution,Provide flood control, water for drinking, agriculture, industry, and recreation
Disadvantages: disrupts ecosystems, people are displaced, dam failure, sedimentation

26. Geothermal
NRG from the heat in the Earth’s crust
Pump water heated water from rock formations and use the water or steam to power turbines

27. Some homes used geothermal heat pumps
US is the world’s larges producer

29. 18-2 Alternative Energy and Conservation
Objectives 1. Describe three alternative energy technologies. 2. Identify two ways that hydrogen could be used as a fuel source in the future. 3. Explain the difference between energy efficiency and energy conservation. 4. Describe two forms of energy-efficient transportation. 5. Identify three ways that you can conserve energy in your daily life.

30. Look around the room…..can you find any instances were energy is being wasted??

31. Alternative energy- describes NRG sources that are still in development

32. Tidal Power
Uses the 2 tide changes
Tide difference needs to be around 16 m
Cost to build is high

34. Ocean Thermal Energy Convection
Warm surface water is used to boil sea water
Water at lower pressure boils at a lower temperature

36. Boiling water turns turbine
Expensive to operate
Environmental effects unknown

37. Hydrogen
Hydrogen is found in every molecule of living thing
Produced water vapor as a byproduct
Takes a lot of energy to produce

38. Energy can be stored in fuel cells (produces electricity chemically)

40. Energy Efficiency
How do we reduce NRG use??
Lifestyle changes?

41. Increase NRG efficiency
The percentage of NRG put into a system that does useful work
NRG out/NRG in X 100
More than 40% of NRG produced is wasted

43. Decease dependence on fossil fuels
Use public transportation
Use more NRG efficient vehicles
Hybrid cars

44. Cogeneration
The production of two useful forms of NRG from the same fuel source
Using wastes for fuel

45. Energy Conservation
SAVING ENERGY!
Use energy efficient devices
Walk!
Carpool
Buy products that use less packaging

46. Turn down your thermostat (68 in winter, 78 in summer)
Unplug unused electrical appliances
Clean vents
Water saving devices
WHAT CAN YOU DO???